What drugs will make rats less cautious/sensible and/or more hungry so they'll go to my snap traps more?

What dosage and how do I deliver it to the rats?

Background info:

The rats trapped in my crawl space I imagine have limited food, if any.
The snap traps are well coated with peanut butter scent but the process is very slow -- one by one.

They have rat mites (blood-sucking parasitic barely-visible mites) and I want them out ASAP.
It's been several months because:

  1. They reproduced down there.
  2. One of the vents got broke open again so a second batch got in. I don't know how many. 25 rats have been trapped so far (2 today and I hear more).

I've checked the house so well. Sealed up with caulk and expanding foam every hole. Checked the roof. Sealed wire mesh on all the plumbing stacks and exhaust vents on the sides of the house.
There's really nothing else. I'm positive it was the broken foundation vent that let the new ones in. But now that everything is sealed securely and won't be broken open again, I think it's only a matter of removing the existing rats.

I don't want to poison them because then they'd die inaccessibly and their mites would swarm the house. They have to die in the traps that I check several times a day, so they can be removed before the mites spread.

  • $\begingroup$ If the rats become less cautious then I would suspect that it's more likely they will come in to your home and cause further problems. If you are laying traps I guess that is something you are trying to stop. You'd be better off seeking professional pest control advice $\endgroup$
    – rg255
    Commented Oct 6, 2016 at 5:35
  • $\begingroup$ Coming from an island rat-eradication standpoint, I would second @Michael_A's point: if you're giving rats a drug with the intention of killing them, make the drug lethal. If you want to kill using snap-traps for ethical reasons (deaths from anticoagulants are not, generally, pleasant), I would suggest habituating the rats to the traps by putting bait on an unarmed trap for several nights until the rats learn to ignore their trap-shyness, then repeating with an armed trap. $\endgroup$
    – bshane
    Commented Oct 6, 2016 at 5:54
  • $\begingroup$ @bshane, yep, I think anticoagulants are cruel and wouldn't use them. I've updated the answer to reflect that. The producers of the rat trap that I linked in my answer have produced good literature for using traps and their traps appear to be highly targeted and effective. $\endgroup$
    – Michael_A
    Commented Oct 6, 2016 at 7:16
  • $\begingroup$ @user193661, Something like the traps in my answer may work well, they use a formulated attractant and their literature may be worth a look. The suggestion from rg255 seems like a good one, a professional may be the fastest option. $\endgroup$
    – Michael_A
    Commented Oct 6, 2016 at 7:29

1 Answer 1


I keep somewhat up-to-date with pest control measures. I haven't heard of chemicals being used to alter rat behaviour but using parasites that alter rat and mouse behaviour (Toxoplasma spp.) has been studied. The infection increases predation rates and also appears to increase the rate at which they are trapped. Toxoplasmosis also affects humans with cats being the main source of infection. I am uncomfortable about approaches that increase the prevalence of toxoplasmosis.

If you're going to the trouble of administering a drug to a pest why not make the drug lethal? The extra step seems unnecessary but I personally would opt for traps given that many poisons (particularly warfarin) seem cruel.

For traps good bait (uncooked bacon, lard, peanut butter, dog biscuits) makes rats;

less cautious/sensible and/or more hungry.

The right trap can make a big difference. This one can self-reload > 20 times and is instantaneous. The linked website contains advice for setting traps.
enter image description here


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .